Table 1.

Mean age and age-standardized characteristics at time of blood draw (1989–1990) among incident colorectal cancer cases (n = 193) and their matched controls (n = 383) and by lowest and highest quintiles of plasma 25(OH)D and 1,25(OH)2D among both cases and controls in the NHS

CasesControls25(OH)D
1,25(OH)2D
Quintile 1Quintile 5Quintile 1Quintile 5
Age, y60.060.060.160.260.860.8
Body mass index, kg/m225.325.026.523.9*26.324.1*
Physical activity, met-hr/wk14.915.212.122.9*13.218.1
UV light from the sun, langleys/d348346340357352355
Dietary intakes per day
    Calcium,§ mg1,0041,0728941,138*1,2121,084
    Vitamin D,§ μg8.79.67.211.0*10.310.0
    Retinol,§ μg retinol equivalents2,0862,2212,0582,2852,1072,186
    Folate,§ μg,402415373454*408411
    Methionine,§ g1.81.81.81.81.91.8
    Red meat, servings1.11.11.21.11.21.1
    Alcohol, g7.66.46.19.37.17.3
Family history of colorectal cancer (%)181512221819
Calcium supplement user (%)36392542*4734
Multivitamin user (%)393629443840
Aspirin user for ≥10 y (%)91087915
Postmenopausal (%)868689828486
HRT user (%)29372149*2946
Past smoker (%)444439554250
Current smoker (%)14131891311
Pack-years of smoking292530252825
  • NOTE: Values are standardized to the age distribution among cases and controls. Controls were matched to cases on year of birth and month of blood draw.

  • * P < 0.01 for cases versus controls or for quintile 5 versus quintile 1.

  • P < 0.05 for cases versus controls or for quintile 5 versus quintile 1.

  • UV sunlight is average available at zip code of residence.

  • § Nutrients include intakes from foods plus supplements.

  • Percentage of women using HRT was calculated among postmenopausal women only.

  • Pack-years were calculated among past and current smokers only.